Flash evaporator rotor



June 27, 1961 .H. w. STRATFQRD 2,990,011

FLASH EVAPORATOR ROTOR Filed OCT.. 3, 1957 2 S11e1,s--Sl1eot 1 O G 6b .w Si /7 zfnl a /3 ummm. y r/// /5 /Qa BY y, 'Z' [gb Anf 'l Nes( June 27, 1961 H. w. sTRATFoRD 2,990,011

FLASH EvAPoRAToR RoToR Filed Oct. 3, 1957 2 Sheets-Sheet A2 INVENTozL Herbe/ JWM/V United States Patent 2,990,011 FLASH YEVAPORATOR ROTOR Y Herbert W. Stratford, Kansas City, Kans., assigner to Stratford Engineering Corporation, Kansas City, Mo., a corporation of Delaware Filed Oct. 3, 1957, Ser. No. 687,952 1 Claim. (CL 159-4) rI'his invention relates to apparatus for dehydrating and degasifying liquids and refers more particularly to such apparatus wherein viscous liquid is introduced into a unique spray device from which it is discharged at high velocity in the form of greatly energized mist particles of micro dimensions into a zone of high v-acuum.

This application is a continuation-impart of my application Serial No. 373,340, iiled August 10, 1953, now

abandoned, and entitled Method vand Apparatus for -Dehydrating and Degasifying Viscous Liquids. The invention is also an improvement over Patent No. 2,368,049 to Charles W. Stratford, entitled Atomizing Evaporator, issued January 23, 1945.

Modern lubricating greases are generally mixtures of soaps and oil, the soaps being compounds of fatty acids and alkali earth metals, and the oils usually petroleum fractions. Both the soaps and oils normally include Va large number of complex chemical'components and frequently are relatively immiscible requiring intensive agitation and intimate mixing to produce a colloidal com-bination having a uniform consistency and stability with respect to oil separation, both in service and over prolonged periods of storage. This thorough dispersion required to produce a high quality grease normally entrains gases and vapors which `are highly undesirable, both 'om the standpoint of chemical stability, appearance and sales appeal.

In the more modern grease plants, the mixing operations in certain stages of the manufacture are conducted under vacuum conditions to alleviate, insofar as possible, the occlusion and inclusion of gases and vapors into the grease. Greases requiring additional processing, such as milling, are aggravated by the dilliculties mentioned since they acquire additional entrainment of air and gases or vapors during such operation.

The invention is designed for separating one or more volatile liquids or gases from liquids of higher boiling points under controlled uniform operating conditions of feed rate, temperature and absolute pressure. By introducing a preheated mixture of liquids into the inventive spray devices hereinafter described, from which the mixture is discharged at high velocity in the form of greatly energized mist particles of micro dimensions into a zone of high vacuum, the low boiling point constituents may be instantaneously flashed into vapor, the stripped particles of nonvolatile liquids impinging and coalescing, without entrainment, on the side wall of the evaporator and draining to the bottom for withdrawal.

Previously, viscous liquid distributing rotors have been employed in low pressure vessels to dehydrate and deaerate such liquids. I have discovered that if it is desired -to employ a rotating spray device, such rotors must be of certain critical orice form -and size to adequately dehydrate and deaerate viscous liquids. Additionally, in combination with this critical orifice lform and size, it is necessary, when the viscosity of the liquid to be dehydrated and deaerated passes a certain point, to employ a vessel of a certain form to `adequately move the viscous liquid after discharging from the rotor downwardly to a removal point. lIf this form of vessel is not employed, the viscous liquid will merely pile up and clot on the sides of the vessel and will not be removable without opening the vessel. Such a construction involves tiring the viscous liquid at high velocity against a surface which "ice is inclined4 upwardly and inwardly relative the vessel whereby to change the outward motion of the liquid into downward motion.

I have also discovered that viscous liquids may be dehydrated and `degasiied in low pressure vessels by employing nonrotating spray devices of critical orifice `form and size. Such spray devices also advantageously are employed in vessels of certain forms. Nonrotating spray devices are less expensive, as well as simpler in construction than rotating-spray devices.

T-herefore, an object of the invention is to provide bothrotating and nonrotating spray devices of the orifice form and opening size which will permit substantially complete dehydration and deaeration of liquids, including extremely viscous liquids, in -a low pressure zone.

Another object of the invention is to provide vessels for employment with said spray devices of forms which permit the substantially complete dehydration and deaeration of very viscous liquids, said vessels shaped so as to change the high velocity outward movement of the liquid from the spray devices into downward motion, thus avoiding piling up and clotting of the viscous liquid on the sides` of the vessel.

Another object of the invention is to provide both rotating land nonrotating apparatus for dehydrating yand degasifying viscous liquids wherein, by controlling the feed rate, the feed temperature, the particle size and the -absolute pressure within the inventive apparatus, it is possible to attain substantially any desired degree of separation of the volatile from higher boiling point liquids.

Another object of the invention is to provide such described dehydrating and degasifying apparatus applicable to the deaeration, dehydration and degasiiication of lube oils. In such use, three evaporators of the inventive type may be normally employed, the rst serving lfor deaeration and dehydration of the oil charge, the second for sulphur dioxide removal after sulphuric acid treating, and the third for brightening the nished water-washed treated oil. The complete dehydration and deaeration of finished oil substantially improves its oxidation and color stability. Average cloudy lube oils rarely contain more than .05 percent of water andl to dry these oils to an acceptable saleable brightness requires that the water content be reduced to .0l percent or less.

Another object of the invention is to provide dehydrating `and degasifying apparatus yapplicable to dehydrate transformer oils to high dielectric specifications. This involves reducing the water content of the finished transformer oil to only a few parts per million.

Another object of the invention is to provide dehydrating and degasifying apparatus capable of removing all traces of low boiling point constituents from oils, along with moisture, absorbed Vair or other gases `and including volatile malodorous compounds such 4as mercap tanS.

Stili another object is to provide such apparatus applicable to removing all detectable traces of alcohols often employed inthe final processing of cosmetic or medicinal oils.

Another object of the invention is to provide dehydrating and degasifying apparatus which may be used for continuous product dehydration. Where several lube oils are to be |blended continuously, with or without additives, the undehydrated ycomponents of the blend and additives may be charged to the inventive apparatus simultaneously. In passing through the apparatus spray device, all components of the finish blend are thoroughly dispersed, as well as dehydrated and deaerataed to the required degree. With practically instantaneous water removal, no precipitation of salts from the additives occurs, even though the additives may be water sensitive. Such precipitated salts frequently cause an undesirable haze which cannot be removed even by complte dehydration or deaeration. U

Still another object of the invention is to provide dehydrating and degasifying apparatus useable for vthe dehydration and deaeration of stable emulsionso'rliquids of highly active surface characteristics, such as sulfonates or similar chemicals, with complete lfreedom from the usual troublesome frothing and foaming that occurs when 4conventional methods of dehydration arei employed.

n Another object of the invention is to provide dehydrating and degasifying apparatus suitable to remove low boiling point fraction hydrocarbons from lube oils treated with ne contact bleaching clay at high temperatures.

tion stocks show that the water content of oils passed through the inventive apparatus may be reduced to a very minute quantity, the reduction being definitely less than is predictable under conditions of theoretically complete equilibrium. This phenomenon may be Well explained Iby the fact that the vapor pressureV of the micro-particles of liquid is much greater than is the vapor pressure of the same liquid in mass. In addition, the enormous com- .posite liquid surface that is exposed in the zone of greatly reduced pressure promotes the e1`n`cient release of lo boiling components or absorbed gases.

Other and further objects of the invention will appear in the course of the following description thereof. In the drawings, which form a part of the instant speci- :cation and are to be read in conjunction therewith, an

embodiment of the invention is shown and, in the Various views, like numerals are employed to indicate like parts.

FIG. l is a side View with parts cut away and in section showing a vessel for employment with the inventive atomizing rotor to permit the dehydration and deaeration of extremely viscous liquids.

FIG. 2 is `a cross section through the inventive rotor as mounted on a low pressure vessel.

FIG. 3 is a view taken along the lines 3 3 of FIG. 2

in the direction of thearrows. l

FIG. 4 is a side View of a vessel for employment with uid takes the form ofa continuous horizontal screen of high velocity greatly ener- :gized mist particles of micro dimensions extending from the orifice of the energizing atomizing rotor to the shaped inside wall of the enclosing vessel.

Referring Yto the drawings, and particularly to FIG. 1, at 10 is showna vessel having an upper portion of its wallV inclined both upwardly and inwardly relative the interiorof -the vessel, relatively vertical side walls, and a lower wall portion inclined both downwardly and inwardly relative the interior of the vessel. On top of the vessel 10 is a motor mounting 11 which supports the motor 12. Referring particularly to FIG. 2, opening 13 lis formed in the topl center portion of the vessel 10 and receiving rim 14 is fastened thereto by welds or other attachments 15. Mounting plate 16 is fixed within the 14..by bolts 17. The motor mounting 11 is welded or otherwise xedly attached to the mounting plate 16 by attaching means or welds 18. Shaft 19 is a continuv4ation of or xed to the drive shaft of the motor 12 and may-be driven in rotation thereby. Plate 16 has opening 20 centrally thereof. Support tube 21 is fixed to the plate '16by bolts 22, extends therethrough, and has fitting 23extending from one side thereof as well as recessed portions ,24 at the lower end thereof. Pipe25 is supportedV by bolt 26 relative to support tube 21 and surrounds shaft 19 with sleeve bearing 27 lixed to the inside surface thereof to maintain the shaft 19 in position rela- Vtive thereto. Feed annulus 28 between the outside of the rpipe 25 and the inner surface of tube 21 connects at its Vupper end with the bore of the fitting 23 to permit feed V'of the uid to be flash evaporated or separated therefrom.

Accelerating disk 29, forming the lower surface of the atomizing rotor, has opening 30 centrally therethrough to receive la lesser diameter portion 19a of shaft 19 therethrough. Nut 31 engages the threaded bottom portion -19b ofthe shaft 19 and xes the accelerating disk relative theend of the shaft. The upper central portion of the accelerating disk abuts the undersurface of the 'slightlygreater diameter portion 19C ofthe shaft. The upper surface of the accelerating disk is also recessed as -at 29a to permit positioning of the lower end of the pipe 25 in close association therewith. The accelerating disk 29 ispreferably angled slightly upwardly in cross section the inventive sprayV head to permit the dehydration and v p las it extends outwardly from the central portion thereof. 'Shrouding disk 32, forming the upper portion of the atomizing rotor, is yfixed by bolts 32a to accelerating vanes 33 which in turn lare fixed to the accelerating disk 29. The shrouding disk 32 is preferably substantially horizontal, that is, xed essentially at a right angle to the shaft 19. vShrouding disk 32 has upwardly extending central portion 34 which is recessed or indented to permit semiengagement of tube 21 and the disk and a portion FIG. 6 is a side, partly sectional view of a second modl FIGS. 1-3 show a rotating spray device employed in a v. low pressure vessel and this modification of the invention will be first described. FIGS. 4-6 show a nonrotati-ng spray device employed in arlow pressure vessel. The operation of the inventive apparatus of FIGS. 153

consists in the impartation of high rotative velocity or tice.v The orifice 35 Vat the periphery of the two disks,

the flashable component from the mixture is'effected by imparting suflicient energy to atomize -the mixed uid through the limited orilce in such a manner as to provide a relatively maximum surface per unit'vo'lume'fof the of the tube 21 to overlie a portion of the top edge of the shrouding disk. The shrouding disk and the tube 21 are spaced one from the other to permit rotation of the shrouding disk relative the tube 21 without contact therewith.

The annulus or space between the accelerating and shrouding disks connects at its inward end with the annulus between the pipe 25 and the tube 21 to permit feed of liquids or uids to be stripped or flashed into the rotatingv disk where the vanes 33 will hurl it through the orito effectively operate to properly disperse thefluids, must be formed by two edges which `are essentially vertically in line 'and not over one fifteen thousandths of an inch apart. `I have discovered that if either the periphery of the' shrouding disk or the periphery of the accelerating disk extends past the other or the orifice therebetween exceeds fifteen thousandths of an inch, the apparatus will not effect sucient dispersal of the liquid or fluid to be stripped or ashed. The upward angling of the accelerating disk 'or,l indeed, the relative `angle of either of the disks relative the shaft 19, is not critical, provided the 'peripheries of both'idiskslare essentially vertically inline andttheorice is. of an aperture in the range of two'to iifteen thousandths of aninch. One one hundredth of an inch vis -about optimum gap for most greases.

Referring to FIG. l, legs 36 support the vessel 10 and an opening is Vpreferably positioned centrally of the bottom of the vessel with draw-off line '36a leadingrtherefrom with pump 36h connected thereto. Vacuumline 36e draws preferably from the top portion of the vessel. Steam or any other inert gas may be supplied to the vessel through pipe 37 and is introduced beneath the atomizing disk. through a hollow perforated ring 38.

In operation of the FIGS. 1-3 modication, the uid to be-ashed or stripped is introduced to the iitting 23 where it passes down the annulus 28 and into the space between the shrouding and the accelerating disks. In the throat of the rotor, the fluid is picked upby the vanes 33 and the rotation of the disk by the shaft V19 moves the uid outwardly where it is projected through the orifice 35 in the form of mist particles of micro dimensions which travel from the orifice to impinge upon the upwardly and inwardly slanted portion of the vessel 10. The disk or rotor must be positioned so the particles impinged on the upwardly and inwardly inclined surface and not the vertical portions thereof so that the outward momentum of the particles may be transformed into downward momentum. The volatile constituents .are completely evaporated from the nely divided energized mist particles during the traverse. 'Ihe volatiles in the form of water vapor, gases and the like are withdrawn from the confined space within the vessel through vacuum outlet 38 which is connected to a vacuum head, not shown. The vacuum in the vessel is normally controlled within the range of one-half inch to ten inches of mercury absolute pressure depending upon the final water content or other volatile content desired in the fluid being treated.

I have conclusively established that an extension of the lip of either the shrouding or accelerating disk as in conventional rotors or the provision of an orice of greater width than fifteen thousands of -an inch, with or without such extension, will prevent practical operation of the rotor and permit the accomplishment of none of the objects of the invention.

As an example of the effect of a lip, tests were conducted in a pilot plant. The original work was donewith a rotor having a four-thousandths inch orifice (below the critical size limit set forth above) but with a one-half inch lip extension over which the discharge from the oriiice passed. In this work it was possible only to reduce the moisture content of the feed stock to .008 percent when operating at one inch mercury absolute and at six inches of mercury absolute there was a moisture content in the product of .14 percent. These values were not considered to be suicient to produce a commercial grade product. By removing the one-half inch lip and closing the orifice to .002 to .004 inch, it was possible to obtain at one inch mercury absolute operating condition, a product having only .0032 percent water. This value achieves the desired objects.

I attribute the remarkable results of my atomizing and dispersing rotor with aligned disk lips and critical orice size to the elimination of shock waves from the rotor. Such shock waves appear when a lip is extended beyond the rotor, or when the orice size is too great. Of course, when the orifice size is greatly excessive, there is no atomizing of the particles suicient to permit stripping thereof of volatiles. However, even when atomization is effected by a reduction in the orifice size and the passage of the uid to be stripped from the rotor to the vessel wall is in the form of particles and not acontinuous film, the stripping is unsatisfactory unless the rotor lips are in line and the orifice is Within the critical size.

Further evidence of the criticality of the yalignment of the rotor lips and the oriiice size is evidenced by the following data. The inventive apparatus Wasrrplaced in operation as a grease polisher. A unit had a sixteen inch diameter rotor which includeda two inch lip on thev rotor cover or shrouding disk. .There was a one-sixteenth inch orifice clearance'between the rotor and the rotor cover or the shrouding. andA accelerating portions of the disk and, when operating withhthis rotor as originally built, althoughA 'there was breakup of the grease into particles, there was absolutely no change in appearance of the grease either from a moisture or air content. Thus, the rotorform employing a lip and a noncritical orice was a complete failure. By removing the two-inch lip from the rotor and closing the orifice between the shrouding disk and accelerating disk in the rotor to one one-hundredth inch, I was able to process grease from a brown, muddy stage to a bright, dark `blue-green appearance by a single pass through the polisher. Y

The following4 tables give specific data on greases 'processed through the inventive apparatus, the second example being the latter example set forth above.

Physical prope'rties of grease No. 1

Operating conditions of deaerator Feed rate, lb./min 142-152. Grease temperature:

Entering, F. 155-195. Leaving, F. 155-195-No change in Vacuum in deaerator, inches temperature observed.

of Hg 25-28. Power consumption No change in thruput using a 10 H.P. motor or a 5 H.P.

Physical properties of grease No. 2

Before After Deaeratlon Deaeration NRLI Grade No. 1 Type of Soap Calcium-Lead Consistency, Worked, 60X 290-319 290-310. Water Content, Percent 0.45-0.50- OAS-.050. Appearance Muddy Bright Brown Dark Blue- Green. Air Content (Net Weight of 35-Lb. Containerv 39.0 41.5.

0.732 Cu. FL), Lbs.

Represents removal of 6.5 0o air Operating conditions of deaerator Feed rate, 1b./min. 142-152. Grease temperature:

Entering, F 155-195. Leaving, F. 155-195--No change in Vacuum in deaerator, inches temperature observed.

of Hg 25-28. `Power consumption No change in 4thruput using a 10 H.P. motor or a 5 H.P. motor.

The actual physical appearance of the mist particles emitted from the inventive rotor having the alignment of the 'disk lips and the criticalroriiice as it passes from -7 vthe periphery of the rotor to the vvessel wall is as follow i Y' lAy uniform thin sheet is discharged from the rotor at a high velocity and'remains in an unbroken sheet for approximately one inch travel. At this point, the sheet breaks' into small particles which continue to travel at ahigh velocityV and they then coalesce in the knuckle radius of the polisher shell.

v The physical appearance of grease passing Ifrom an aligned lip rotor having an'excessive opening therein is as follows: p l f The discharge from` the rotor is in bands with a thickness determined by the orifice opening and the Width of the bands determined'by the `feed rate and velocity discharge from the rotor. In normal operation, these bands are about one inch wide and do not have a tendency to break into smallfparticle sizes in their path from the rotor to the knuckle radius of the shell.

The physical appearance of grease passing from a rotor having an extension of the lip of either disk or `such extensionV and an excessive oriiice is as follows:

In this instance the discharge from the rotor has a nonuniformity of thickness which is created by shock -waves thattravel over the extendedv lip and increase in magnitude as they approach the periphery and Ifurther discharge from the rotor inA bands that do not break into small particles in its path from the rotor lip to the coalescing knuckle.

Thus it is obvious 'that 'the inventive Vrotor having aligned lips and a critical orice size actually demonstrates physically the smooth breakdown of the uid into mist particles of micro dimensions which pass smoothly without shock waves from the inventive rotor to the vessel wall, thus permitting stripping of the volatiles during this passage. Y

The modifications of the invention illustrated in FIGS. 4-6 show grease polishers employing spray heads which are nonrotating. FIGS. 4 and 5 illustrate such a nonrotating spray head wherein a diaphragm bellows controls the orilice gap through which the grease is forced by pressure from the charge pump. By regulating the pressure Within the diaphragm either from the grease feeding Vline or from an auxiliary pressure supply, the thickness of the film discharging from the rotor can be regulated. The modification of FIG. 6 shows a spray head arrangement employing springs to regulate the Yorifice discharge which employs limit stops to regulate the orifice discharge which employs limit stops to regulate the minimum oriice.

Referring then lirstto FIGS. 4 and 5, at 40 is shown a vessel having an upper portion ofY its wall inclined both upwardly and inwardly relative the interior of the Wessel, a limited portion of the side walls relatively vertical and a lowerY wall portion inclined both downwardly and inwardly relative the interior of the vessel. These Wall portions are shown at 40a, 40h and 40C, respectively. Referring particularly to FIG. 5, opening 41 is -formed in the top center portion of the vessel shell 40 and mounting plate 42 having central opening 43 therein is xed to the enlarged portion 41a of opening 41 by bolts 44. Shrouding disk 45v is tted by its upwardly extending portion 46 into opening 43. L- tting 47 has peripheral flange -48 at its lower end which is engaged by bolts 49 which also engage threaded openings 50 in the upper ilange portion 511 of the shrouding disk 45. Vanes 52 are iixed in the throats of shrouding disk 45 and L-iitting 47.V Feed inlet 53 extends laterally -from L-itting 47, Opening 54 is formed in the upper central portion of the L-littingV 47. Mount55 is 'fixed by bolts 56 to the top of the L-tting 47. Diaphragm housing 57 has upper and lower portions 58 and 59 fixed to one another by bolts 60 engaging anges thereon and diaphragm 61 is also positioned between the Vtwo portions V58 and 59 and engaged by the anges thereon. Input opening `62 in upper diaphragm por- 'A15 tion 58 has threaded input iitting 63 therein with pressure medium 'feed line 64 attached thereto. Shaft 65 extends through the diaphragm andisV engaged therethrough by nuts and washers 566 and 67 oh'the threaded upper end thereof: Opening 68 in diaphragm portion 59 permits the extension of shaft -68 downwardlyy therethrough, the shaftextending also through opening 54 in L-'tting 47 and passing through sealing gland assembly 69 between the diaphragm and the L-itting. Shaft 65 Vhas an' enlarged portion I65a below the opening 54 which extends centrally of the L-tting opening and the Shrouding disk upper portion 46 to engage bottom disk 70 whose outer edge is substantially vertically in line with the outer edge 45a of the shrouding disk. Application ofv greater pressure within the upper diaphragm portion 58 will force'diaphragm 61 downwardly carrying shaft 65 therewith to move the Shrouding and lower disc edges away from one another to increase the gap therebetween. The enlarged portion 65a of the shaft 65 abutting the top of the L-tting 47 limits the upward motion of the lower disc 70. Secondary pressure line 71 engages tting 72 threaded into opening 73'in the lower diaphragm portion 59 to aid in regulating the' position of the diaphragm 61. 'I'he diaphragm assembly is fixed to the mounting 55 by bolts 74. Vacuum exhaust take-off 75 preferably, but optionally, extends to the wall 40e` of the vessel 40 with its intake end positioned centrally under the lower disk 70 as seen in FIG. 5. The attachment Itting 76 on the outer end thereof may be coupled with any suitable exhaust line.

Referring now to FIG. 46, the like parts of the evacuation vessel are numbered like FIGS. 4 and 5. The shrouding disk in this construction is exactly the same as that shown in the modiication of FIG. 5 and thus is like numbered as well. A slight change lies in the provision of openings 77 and bolt abutments 78 in the outer edge of the Shrouding disk. An L-itting similar to that of F-IG. 5 is provided attached to the upper face of plate 42 and thus is numbered alike as are its attaching parts. However, the difference in this L-litting lies in that there is no central upper opening `54 for the extension therethrough of a shaft attached to the lower disk. In this modification, the lower disk 79 having openings 80 arranged peripher-ally of its outer edge to match opening 77 in the shrouding disk is fixed relative the Shrouding disk by two constructions. In the first place, limit stops 81 limit the closeness allowed of the two disks while bolts 82 extend through openings 77 and '80 and have springs 83 encircling the bolts and regulated in tension against the underside of the lower disk by nuts and washers 84 and 85 threaded on the lower ends of the bolts 82. The upper heads of the bolts 82 as shown at 82a rest on the leveling abutment 78 formed on the Shrouding disk. The vacuum take-oil in this construction is the same as in the previous construction and thus is like numbered. Steam or any other inert gas may be supplied to the vessels containing the apparatus of FIGS. 5 and 6 through pipes and may be introduced through hollow perforated rings 86 (FIG. 4) on the opposite side of the disk irom vacuum line 76.

The difference in operation between the twounits lies only in the manner of regulating the opening between the upper and lower disks in the spraying devices. Lower disk 79 has upwardly extending central portion 86 to guide the input viscous fluid uniformly outwardly in the channel 87 formed between the two disks. The required pressure for forcing the viscous uids outwardly between the aligned edges 45a and 70a of both the modilications of FIG. 6 and FIG. 5 depend largely on the Viscosity of the liquids. The pressure should be suicient to drive the material outwardly through the orifice between the two disks to impinge at high velocity on the knuckle radius 40a ofthe vessel 40. The crucial range of orifice gap must be maintained within the two one-thousandths of an inch to fifteen one-thousandths of an inch range previously set forth relative the rotor modification. Results obtained with the modication shown in FIGS. and 6 are the same as those set forth relative the rotating device. The description of the appearance of the ilm discharged from the inventive rotor is the same applied to the hlm discharged from the modification of FIGS. 5 and 6.

From my experimental work and observations, I conclude that the orifice size employed in the rotating and nonrotating spraying devices disclosed above is valid over the range given. However, within this range, the smaller the orice for a given feed stock, the higher the eciency of the spraying device insofar as dehydration is concerned. On gas oils and very low viscosity lube oils, it would appear that an orifice in the range of threethousandths inch to iive-thousandths inch would be practical for commercial application. This would also be true when handling transformer oils. When handling medicinal oils having a viscosity of, say, 400 SSU at 100 F., the orifice would optimally be six-thousandths inch or less. On lube stocks, eight-thousandths inch would appear to be optimum for an orifice size and, in higher viscosity materials such as grease and sulfonates, it has appeared that the maximum permissible oriice should be less than fteen-thousandths inch. In the transformer oils, `a residual water content of live ten-thousandths percent is permissible. In medicinal oils, a residual water content of 0.005 percent is permissible and, in lube oils, the permissible water content is less than 0.01 percent. Greases are allowed by the industry to have a residual water content of from 0.5 to 1.5 percent while sulfonates may not exceed .05 percent residual water. The above optimum orifices refer to these requirements. Thus, transformer oils may employ an orice from two-thousandths inch to four-thousandths inch, medicinal oils on'ces from twothousandths inch to six-thousandths inch, lube oil from two-thousandths inch to eight-thousandths inch and greases and sulfonates from two-thousandths to uiteen-thousandths inch. The above data indicates that a selected orice width in said range is lesser for higher viscosity liquids and greater for lower viscosity liquids being treated, in order to achieve comparable results in dehydration and in the interest of higher eiciency.

In the case of the commercial size ash evaporators handling lube stocks with an extended lip, the discharge from the rotor is Very definitely uneven and it appears that the majority of the material being discharged from the rotor is coming in heavy strings projected from the rotor vanes. In other words, from a visual inspection, it appears that the discharge is coming oif the rotor similarly to that which would be expected `from -a rotor with drilled holes except that there is a substantial trailing edge to each discharge stream. In the case of grease, the discharge is entirely different in that severe shock waves are imposed on the uid flowing across the extended lip and, in this instance, it appears that the flow comes olf as Waves on the sea shore. This ow has been substantiated by taking a spatula and passing perpendicularly through the discharge yfilm with the resultant deposit on the spatula being extremely corrugated.

Thus it is seen that by providing both rotating and nonrotating spray devices with aligned lips and severely limited orices, I have been able to solve dehydrating and deaerating problems not previously solved by the art. I have provided new results never before accomplished.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the structure.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claim.

As many possible embodiments may be made of the invention Without departing from the scope thereof, it is to be understood that all material hereinabove set forth or shown in the drawings is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim:

An atomizing rotor for treating a liquid containing at least two constituents of differing volatility, one more volatile than any other, comprising a pair of coaxially aligned rotatable discs spaced apart to form a narrow annular space therebetween, which tapers from a thicker throat portion to a narrow orifice having a width no greater than .015 inch and no less than .002 inch defined by the aligned peripheral lips of the discs, means rigidly fixing said discs together for rotation together at a given fixed spacing from one another within said range, the selected orifice Width in said range being lesser for higher viscosity liquids and greater for lower viscosity liquids being treated to achieve comparable results, means for feeding said liquid between said discs into said annular space, and means for simultaneously rotating said discs about their common axis.

References Cited in the le of this patent UNITED STATES PATENTS 2,103,887 Bowen et al. Dec. 28, 1937 2,368,049 Stratford Ian. 23, 1945 2,540,390 Gorgerat et al. Feb. 6, 1951 2,621,966 Jehlicka Dec. 16, 1952 2,642,950 Clark et al. June 23, 1953 2,797,767 Brooke et al .Tuly 2, 1957 2,850,085 Nyrop Sept. 2, 1958 

